But couldn't God have made them change?

Of course, the answer to that question (assuming you believe in God) is "of course", because if He did create everything, then He created evolution as well. It was nice of Him to make things work in a consistent manner across the universe so that we're not constantly at the mercy of an individual's whim, though.

The thing that irritates me the most about ID (other than the apparent desire to be ignorant) is that it assumes that God is incompetent enough to need to constantly come back to his creation and tweak it all the time. Wouldn't a greater God have been able to set things in motion and not see what happens, but know what would happen beforehand and have designed it to work that way? Or maybe this universe is running under an interactive debugger.

It seems to me that evolution is not inconsistent with there being a God, but ID ignores what humans can observe and assumes a less competent God.